Lesson 13: Food & Health February 3, 2006 ENVIR 202: Lesson No. 13 Food & Health February 3, 2006 February 3, 2006 Chuck Treser Chuck Treser University of Washington University of Washington Program on the Environment Program on the Environment ENVIR 202: Lesson 13 1 Overview � Food Quantity Problems � Food Requirements � Food Quality Problems � Foodborne Disease ENVIR 202: Lesson 13 2 Food Properties � Food should be . . . � Safe � Attractive � Abundant � Nutritious ENVIR 202: Lesson 13 3 ENVIR 202: Population & Health 1
Lesson 13: Food & Health February 3, 2006 Food Quantity � Production: � World-wide, most suitable land is already under cultivation � Yield per acre – increasing, but at slower rate � Yield per unit of energy consumed in production – fishing, livestock are very costly in energy, produce high energy density but low quantity; food webs differ markedly in this respect. � Effects of over-harvesting: exceed rate of reproduction � Effects of habitat destruction ENVIR 202: Lesson 13 4 Food Quantity � Storage: � Spoilage (oxidation, microbial decay): salting, smoking, refrigeration, chemical antioxidants (preservatives), irradiation � Damage by vermin: rodents, arthropods � Other mechanisms: dehydration ENVIR 202: Lesson 13 5 Food Quantity � Distribution: � Transportation – dependent on local organization and infrastructure � Cost to consumer – poverty, influence of intermediate participants ENVIR 202: Lesson 13 6 ENVIR 202: Population & Health 2
Lesson 13: Food & Health February 3, 2006 Food Requirements � Metabolic (Energy) Demand: � Depends on age, gender, body surface area, physical activity � Common units for: � measuring energy: joules, ergs, kilowatt- hours, foot-pounds, British Thermal Units, kilocalories; � for measuring rate of energy consumption: watts, horsepower] ENVIR 202: Lesson 13 7 Basal (Resting) Metabolic Rate Kcal/(m 2 -hr) Age Male Female 5 53.0 51.6 20-24 41.0 36.9 40-44 38.3 35.3 50-54 37.2 34.5 Body Surface Area(m 2 ) = 0.202 x BW(kg) 0.425 x H(m) 0.725 ENVIR 202: Lesson 13 8 Examples � Example 1: � 21 year old female, 5’6” tall, 61 kg (134 lbs.) � Body surface area = 1.667 m 2 � Resting metabolic rate = 1476 Kcal/day � Example 2: � 57 year old male, 6’ 1.5” tall, 82 kg (180 lbs.) � Body surface area = 2.067 m 2 � Resting metabolic rate = 1845 Kcal/day ENVIR 202: Lesson 13 9 ENVIR 202: Population & Health 3
Lesson 13: Food & Health February 3, 2006 Effect of Exercise Energy Rate* Activity (Kcal/m2-hr) Sleeping 35 Sitting 50 Standing 85 Walking at 3 mile/hour 140 Bicycling 250 Swimming 350 Running 600 *20 year old male ENVIR 202: Lesson 13 10 Calories in Food Kcal/g Component Carbohydrate 4 Fat 9 Protein 4 Ethanol 7 Note: 1 metabolic Kcal = 1 dietary Calorie ENVIR 202: Lesson 13 11 Example � For a diet including 36% of total calories as fat: � 500 g of food components (1.10 lb) provides 2500 Kcal. � The balance between intake of food and energy consumption determines storage and weight stability. ENVIR 202: Lesson 13 12 ENVIR 202: Population & Health 4
Lesson 13: Food & Health February 3, 2006 Body Mass Index (BMI) � BMI (kg/m 2 ) = weight (kg) / height (m 2 ) � Underweight: BMI <20 � Overweight: BMI >25 � Obese: BMI >30 � Health risks for those overweight: � diabetes � heart disease ENVIR 202: Lesson 13 13 Food Quantity � Conditions resulting from deficiencies: � Protein (8 essential amino acids) – kwashiorkor � Total calories - marasmus � Iron – anemia � Iodide – goiter � Vitamin A – blindness � Vitamins B – beri-beri, pellagra � Vitamin C – scurvy � Vitamin D – ricketts � Other essential trace components: � cobalt, zinc, magnesium, selenium, folic acid ENVIR 202: Lesson 13 14 Energy Density in Foods: � Energy density = total calories/g food � Includes effects of bone, water, non- digestible components such as fiber ENVIR 202: Population & Health 5
Lesson 13: Food & Health February 3, 2006 Food Energy Density � Low energy density foods: Contain relatively large amounts of air (popcorn, ice cream), water (soft drinks, fresh fruits and vegetables), or fiber (fruits and vegetables) � High energy density foods: Contain relatively large amounts of fat (animal meats), and are heavily processed to remove air, water, fiber (TV dinners, Powerbars). � These properties have important considerations for world-wide nutrition and health. ENVIR 202: Lesson 13 16 Food Properties � However, food is susceptible to: � Spoilage � Contamination � Adulteration E. coli Bacterium � which can render it unfit to eat ENVIR 202: Lesson 13 17 Food Quality � Deliberate Additives (regulated by Food and Drug Administration and the US Dept. of Agriculture, based on risk assessment) � Preservatives - eg, benzoic acid, sorbic acid, propionic acid � Flavorings - natural, artificial � Texture Modifiers - eg, gums, emulsifiers � Genetically Modified Organisms (GM0) - pest resistance, flavor ENVIR 202: Lesson 13 18 ENVIR 202: Population & Health 6
Lesson 13: Food & Health February 3, 2006 Food Quality � Unintentional Contaminants (FDA, USDA, US Environmental Protection Agency, State and Local Health Departments) � Pesticides, fertilizers, pollutants in soil and water � Antibiotics and other animal feed additives ENVIR 202: Lesson 13 19 Unintentional Contaminants � Microbiological contaminants - from animals, water, human food handlers (preparation, serving) � Infectious agents - food borne infection E.g., salmonella, campylobacter, E. coli � Microbial toxins - food borne intoxication E.g., botulism, staphyloccal enterotoxin, bacillus cereus toxin, aflatoxin ENVIR 202: Lesson 13 20 Foodborne Disease � There are two types of foodborne illness � Infections � Intoxications ENVIR 202: Lesson 13 21 ENVIR 202: Population & Health 7
Lesson 13: Food & Health February 3, 2006 Foodborne Disease Continued � Infections are caused by: � The presence of micro- organisms in large numbers which multiply in the gut and overwhelm the body’s defenses ENVIR 202: Lesson 13 22 Foodborne Infections � Amebic Dysentery � Brucellosis � Campylobacter enteritis � Diarrhea(Acute) � Viral gastroenteritis ENVIR 202: Lesson 13 23 Foodborne Infections Continued � Salmonellosis � Shigellosis � Trichinosis � Typhoid Fever � Infectious Hepatitis Mallon as she was portrayed in an ENVIR 202: Lesson 13 illustration in the June 20, 1909, 24 edition of The New York American ENVIR 202: Population & Health 8
Lesson 13: Food & Health February 3, 2006 Foodborne Disease Continued � Intoxications are caused by chemicals or “toxins” � Produced by micro-organisms, or by � Contamination with natural or manufactured chemicals ENVIR 202: Lesson 13 25 Foodborne Intoxications � Botulism � Staphylococcal food poisoning � Clostridium perfrigens � Bacillus cereus ENVIR 202: Lesson 13 26 Foodborne Toxins Continued � Scromroid fish poisoning (Histamine) � Ciguatera fish poisoning � Paralytic shellfish poisoning (PSP) � Amnesic shellfish poisoning (domoic acid) � Puffer fish poisoning (tetrodotoxin) ENVIR 202: Lesson 13 27 ENVIR 202: Population & Health 9
Lesson 13: Food & Health February 3, 2006 Types of Pathogens � Sporeforming Bacteria � Viruses � Clostridium botulinum � Hepatitis A � Clostridium perfringens � Norwalk Virus � Bacillus cereus � Non-sporeforming Bacteria � Salmonella spp. � Campylobacter � E. coli O157:H7 � Staphylococcus aureus � Listeria monocytogenes ENVIR 202: Lesson 13 28 Normal Symptoms of Foodborne Disease � Nausea � Vomiting � Diarrhea � Cramps � Headache � Fever � Chills � Body Aches ENVIR 202: Lesson 13 29 Complications of Foodborne Illnesses � Kidney Damage � Blood Poisoning � Chronic � Pneumonia Sporadic Toxoplasmosis � Arthritis � Neurological (2% will trigger) � HUS Damage ( 5-20K cases/ yr) � Pancreatic � Guillian Barre Infections Syndrome � Chronic Illness - likely to occur in 2-3% of FBIs ENVIR 202: Lesson 13 30 ENVIR 202: Population & Health 10
Lesson 13: Food & Health February 3, 2006 High Risk Individuals � Infants � Immuno-compromised people: � Children � Recent major surgery � Pregnant Women � Pre-existing or chronic � Senior Citizens illness � People taking � HIV / AIDS medications: � Diabetes � Antibiotics � Cancer � Antacids � Liver or Kidney Damage � Immuno-suppressive � Ulcers drugs ENVIR 202: Lesson 13 31 Contributing Factors � Factors Contributing to an increased risk of Foodborne Illness � Aging Populations � Lifestyles of the Public � New and Emerging Pathogens � Increase in High Risk Individuals � New Processing Methods for Foods � New Sources of Foods - Geographic ENVIR 202: Lesson 13 32 Foodborne Disease Outbreaks United States, 1993-1997 Chemical 5% 24% Bacteria Viral 24% 2% 68% Bacterial Viral Chemical Parasitic Unknown 5% 1% 68% ENVIR 202: Lesson 13 33 ENVIR 202: Population & Health 11
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